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    <title>ShellCheck: SC2073 – Escape `\<` to prevent it redirecting (or switch to `[[ .. ]]`).</title>
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    <h1>SC2073 – ShellCheck Wiki</h1>
    <a href="https://github.com/koalaman/shellcheck/wiki/SC2073">See this page on GitHub</a>
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    <h2 id="escape--to-prevent-it-redirecting-or-switch-to---">Escape
<code>\&lt;</code> to prevent it redirecting (or switch to
<code>[[ .. ]]</code>).</h2>
<h3 id="problematic-code">Problematic code:</h3>
<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="SC2073.html#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="bu">[</span> <span class="st">&quot;aardvark&quot;</span> <span class="er">&lt;</span> <span class="st">&quot;zebra&quot;</span> <span class="bu">]</span></span>
<span id="cb1-2"><a href="SC2073.html#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="cf">then</span></span>
<span id="cb1-3"><a href="SC2073.html#cb1-3" aria-hidden="true" tabindex="-1"></a>  <span class="bu">echo</span> <span class="st">&quot;Alphabetical!&quot;</span></span>
<span id="cb1-4"><a href="SC2073.html#cb1-4" aria-hidden="true" tabindex="-1"></a><span class="cf">fi</span></span></code></pre></div>
<h3 id="correct-code">Correct code:</h3>
<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="SC2073.html#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="bu">[</span> <span class="st">&quot;aardvark&quot;</span> <span class="dt">\&lt;</span> <span class="st">&quot;zebra&quot;</span> <span class="bu">]</span></span>
<span id="cb2-2"><a href="SC2073.html#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="cf">then</span></span>
<span id="cb2-3"><a href="SC2073.html#cb2-3" aria-hidden="true" tabindex="-1"></a>  <span class="bu">echo</span> <span class="st">&quot;Alphabetical!&quot;</span></span>
<span id="cb2-4"><a href="SC2073.html#cb2-4" aria-hidden="true" tabindex="-1"></a><span class="cf">fi</span></span></code></pre></div>
<p>or optionally in Bash/Ksh:</p>
<div class="sourceCode" id="cb3"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb3-1"><a href="SC2073.html#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="kw">[[</span> <span class="st">&quot;aardvark&quot;</span> <span class="ot">&lt;</span> <span class="st">&quot;zebra&quot;</span> <span class="kw">]]</span></span>
<span id="cb3-2"><a href="SC2073.html#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="cf">then</span></span>
<span id="cb3-3"><a href="SC2073.html#cb3-3" aria-hidden="true" tabindex="-1"></a>  <span class="bu">echo</span> <span class="st">&quot;Alphabetical!&quot;</span></span>
<span id="cb3-4"><a href="SC2073.html#cb3-4" aria-hidden="true" tabindex="-1"></a><span class="cf">fi</span></span></code></pre></div>
<h3 id="rationale">Rationale:</h3>
<p>You are using the operator <code>&lt;</code> or <code>&gt;</code> in
a <code>[</code> test expression.</p>
<p>In this context, it will be considered a file redirection operator
instead, so <code>[ "aardvark" &lt; "zebra" ]</code> is equivalent to
<code>[ "aardvark" ] &lt; ./zebra</code>, which is true if there exists
a readable file <code>zebra</code> in the current directory.</p>
<p>If you wanted to compare two strings lexicographically
(alphabetically), escape the <code>&lt;</code> or <code>&gt;</code> with
a backslash as in the correct example.</p>
<p>If you want to compare two numbers numerically, use <code>-lt</code>
or <code>-ge</code> instead.</p>
<h3 id="exceptions">Exceptions:</h3>
<p>None.</p>
<h3 id="related-resources">Related resources:</h3>
<ul>
<li>Help by adding links to BashFAQ, StackOverflow, man pages, POSIX,
etc!</li>
</ul>
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